1. Field of the Invention
The invention is directed to an improved damper or shock absorber embodying a piezoelectric valve disposed inside the damper.
2. Description of the Prior Art
From the prior art, dampers for vehicles are known whose characteristic shock absorber values can be adjusted via hydraulic proportional valves and adapted to various driving situations. These proportional valves continuously control the fluid flow in the damper, for instance with the aid of a control piston that is moved by an exciter coil. The proportional valves are either flanged to the damper or integrated in the piston ram of the damper. An additional sensor, which is disposed on the wheel suspension, furnishes information about the state of indentation of the damper. Acceleration sensors or travel sensors with a transmission connecting rod can be used as sensors. Associated evaluation and control units are either disposed centrally in the vehicle or can be located in decentralized form on the flanged-on proportional valve. The proportional valve can control the main fluid flow indirectly, for instance; that is, a small secondary flow is regulated directly by a small control piston and forms a pressure difference compared to the main valve. On the basis of this regulated pressure difference, the main fluid flow in the main valve is established. The reaction time of the damper is limited by the transient response of the proportional valve.